Anomalous degradation behaviors under illuminated gate bias stress in a-Si:H thin film transistor

Tsai, Ming-Yen; Chang, Ting‐Chang; Chu, Ann-Kuo; Hsieh, Tien-Yu; Lin, Kun-Yao; Wu, Yih‐Min; Huang, Shih‐Feng; Chiang, Cheng-Lung; Chen, Po‐Lin; Lai, Tzu-Chieh; Lo, Chang‐Cheng; Lien, A.

doi:10.1016/j.tsf.2014.09.050

Cited by 6 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The concentration of K + ions was more than three times higher than in sample A. This findin g implies that K + ion accumulation close to the back c hannel causes a parasitic TFT effect [3], which in turn causes the hump phenomena. After closely examining our process flow, we found that the main source of K + ions is KOH, which is a component of CF develop er.…”

mentioning

confidence: 78%

P‐1.24: Investigation of Abnormal Degradation Behaviors under Negative Bias Stress in a‐Si:H TFTs

Jiang,

Xu,

Song

et al. 2024

Symp Digest of Tech Papers

View full text Add to dashboard Cite

mentioning

confidence: 78%

P‐1.24: Investigation of Abnormal Degradation Behaviors under Negative Bias Stress in a‐Si:H TFTs

Jiang,

Xu,

Song

et al. 2024

Symp Digest of Tech Papers

View full text Add to dashboard Cite

“…16,21,27 Recently, however, as the stress voltage increases, the turnaround phenomenon of the threshold voltage shift was reported, attributed to the compensation of hole trapping and state creation. 28 Currently, we observe this turnaround behavior under high intensity illumination, which has not been reported yet.…”

Section: Introductionmentioning

confidence: 99%

“…The gate bias instability of a-Si:H TFTs has been studied for several decades and has generally been explained by two mechanisms: charge trapping within the gate insulator associated with trap sites and defect states created by the breaking of weak bonds within a-Si:H. − At negative gate bias stress, the threshold voltage commonly shifts toward the negative gate voltage region due to the hole trapping, in which the holes are injected from a-Si:H active layer. ,, Recently, however, as the stress voltage increases, the turnaround phenomenon of the threshold voltage shift was reported, attributed to the compensation of hole trapping and state creation . Currently, we observe this turnaround behavior under high intensity illumination, which has not been reported yet.…”

Section: Introductionmentioning

confidence: 99%

Abnormal Behavior of Threshold Voltage Shift in Bias-Stressed a-Si:H Thin Film Transistor under Extremely High Intensity Illumination

Han

Park

Kim

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

We report on the unusual behavior of threshold voltage turnaround in a hydrogenated amorphous silicon (a-Si:H) thin film transistor (TFT) when biased under extremely high intensity illumination. The threshold voltage shift changes from negative to positive gate bias direction after ∼30 min of bias stress even when the negative gate bias stress is applied under high intensity illumination (>400 000 Cd/cm(2)), which has not been observed in low intensity (∼6000 Cd/cm(2)). This behavior is more pronounced in a low work function gate metal structure (Al: 4.1-4.3 eV), compared to the high work function of Cu (4.5-5.1 eV). Also this is mainly observed in shorter wavelength of high photon energy illumination. However, this behavior is effectively prohibited by embedding the high energy band gap (∼8.6 eV) of SiOx in the gate insulator layer. These imply that this behavior could be originated from the injection of electrons from gate electrode, transported and trapped in the electron trap sites of the SiNx/a-Si:H interface, which causes the shift of threshold voltage toward positive gate bias direction. The results reported here can be applicable to the large-sized outdoor displays which are usually exposed to the extremely high intensity illumination.

show abstract

“…Currently, mainstream TFT technologies include amorphous Si (a-Si), amorphous metal-oxide semiconductors (mainly a-IGZO) and low-temperature polycrystalline silicon (LTPS). Although being the main driver for liquid-crystal displays for years, circuits designed in a-Si technology suffer from very low mobility (~0.5-1cm²/V) and lack of electrical stability (threshold voltage shift) [16], [17]. Amorphous metal-oxide devices such as a-IGZO TFTs feature higher mobilities (~12cm²/V), excellent large-area uniformity, submicron channel lengths and their stability under bias stress is much better compared to a-Si TFTs [18], [19].…”

mentioning

confidence: 99%

Thin-Film Transistor-Based Sensor Interface Circuits Enabling Distributed Local In-Module Solar Cell Temperature Monitoring

Faramarzi

Luo

Poortmans

et al. 2024

IEEE J. Solid-State Circuits

View full text Add to dashboard Cite

Accurate efficiency prediction, improved reliability and extended lifetime of solar modules are key driving factors for investment and research in photovoltaic (PV) systems. Enhanced performance and more refined models are realized by incorporating data derived from localized monitoring of solar modules. This work combines interface circuits designed in flexible thin-film transistors (TFT) with distributed temperature sensors integrated in solar cell lamination enabling in-module within-cell PV monitoring. A TFT Multiplexer selects between sensors and is commanded through Serial Peripheral Interface (SPI) to reduce the IO connections, while the low offset unity-gain TFT buffer enables precise signal transfer. The in-cell sensors together with TFT read-out circuitry demonstrate accurate outdoors temperature monitoring, comparable to Silicon integrated circuits.

show abstract

Anomalous degradation behaviors under illuminated gate bias stress in a-Si:H thin film transistor

Cited by 6 publications

References 39 publications

P‐1.24: Investigation of Abnormal Degradation Behaviors under Negative Bias Stress in a‐Si:H TFTs

P‐1.24: Investigation of Abnormal Degradation Behaviors under Negative Bias Stress in a‐Si:H TFTs

Abnormal Behavior of Threshold Voltage Shift in Bias-Stressed a-Si:H Thin Film Transistor under Extremely High Intensity Illumination

Thin-Film Transistor-Based Sensor Interface Circuits Enabling Distributed Local In-Module Solar Cell Temperature Monitoring

Contact Info

Product

Resources

About